Valve mechanism for internal-combustion engines



June 7 1927.

VALVE MECHANISM FOR INTERNAL COMBUSTION ENGINES G. FORNACA Filed March 20. 1926 Patented June 7, 1927.

eurno rormaca,

or roam, i'r-ALY.

. VALVE mncnANfsr/r FOR INTERNAL-COMBUSTION ENG1NES.

Application filed March 20, 1926, Serial No; 96,229, and in Italy March-25, 1925,

This invention relates to an internal combustion engine having its valves grouped in sets and provides mechanism for simul- 'taneously operating the valves of each set,

characterized in that the operating cams for said valves are symmetricall disposed on both sides of a camshaft bearlng so that the camshaft is not subjected to bending stress,

' said bearing having a guide for a cross-piece onwhich the cams act near. the-points o-f support 'of the valve stems and through several which the valves are moved.

By" this arrangement all fiexure of the 3 3 camshaft is eliminated and said shaft is subjected only to torsionalstresses for which reason it can be made much lighter and intermediary supports can be omitted.'

The cross-piece can also be very light and is therefore easily made by a stamping .or pressing process.

Moreover, great precision in the operation of the mechanism is obtainable although the arts do not require to be so 'very accurate y constructed, thus realizing a great economy in manufacture, as well as facilitatin the assemblage and replacement of the diifbrent members.

Slight displ(acement mechanism camshaft, cross-piece, valve tappets) and the valve stems may take place without any inconvenience, as it is not essential that the camshaft axis and the axis of the valve stems be exactly in the same plane nor in absolutely parallel planes.

, B-B of Fig. 3; and j By wayof example, one constructional form of the mechanism, applied to an engine having two camshafts, is illustrated on the accompanying drawing, whereonz- Fig. 1 is a cross section in the plane A--A. of Fig. 3;

Fig. 2 is a longitudinal section in the plane .Fig. 3 is a plan.

Referring to the drawing, the upper part 1 of the cylinder head is fitted with guides 2 for the stems of the valves 3, and has intep gral shoulders 4, 14 to which are secured, by

means of screws 8, the bearings 5, 5'. supporting the camshafts 6 on each of which are cams 7 disposed in pairs, one on either side of a camshaft bearlng.

Each bearing part 5 has an extension 9 serving as a guide for a cross-piece 10 formed with split ends in which adjustable valve tappets 11 are secured by means of screws 11. The cross-piece has twosurfaces 12, 12

between the operating respondin lve mechanism for internal comf bustion eng1nes, compr1s mga plurahty of- PA ENT" o FicE.

engaged by the cams T, 7 near the tappets 11.

which-ere co-axial with the valve stems 3.

The shoulders '4, 14 form a box or casing rational as, when there is a maximum stress,

that is, when the valves begin to open, the cross-pieceJO isquite near the bearing support and therefore the bending moment is' very small. 7

The valve mechanism. can be rapidl and easily dismounted and remounted an any required adustment can be made at the valve tappets'l'l." v I What I claim is:

1. A valve mechanism. for internal combustionengines, comprising a plurality of valves grouped in sets and having stems in parallel relation, a crosspiece bearing on the end of the stem of each valve 'of a set, a shaft arranged above the eross;pieces, bearings for said shaft mounted between/the valve stems of each set, and cams moimted on said shaft in proximity to and laterally of each bearing, each set of cams co-operating with a cross-piece for actuating the corset of valves. 2. A va valves rouped in sets, and. having stems in aralle? relation, a cross-piece bearing on the endof the stem of each valve of a set, a shaft' arranged above the cross-pieces, bearings for said shaft mounted between the valve stems of each set, a guide rod for each cross-piece carried by each bearing, and cams mounted on the shafts in proximity to and laterally ofea'ch bearing, each set of cams 3; A valve mechanism for internal com bustion engines, comprising a plurality of valves grouped in sets, and having stems in parallel relation, a cross-piece bearing on the end of the stem of each valve of a set,

j a shaft arranged above the cross-pieces,

bearings for said shaft, mountedbetween the valve stems of each set, extensions formed on each, bearing constituting guides for said cross pieces, and cams mounted on the shafts in proximity to and laterally of each bearing, each set of cams co-operat-- ing with a cross piece for actuating the corresponding set of'valves.

4. A valve mechanism for internal com-- bustion engines, comprising a plurality of valves arranged in pairs and having stems in parallel relation, a cross piece for each pair of valves for actuating the stems of the latter, a shaft extending above a plurality of cross-pieces, bearings for the shaft fixed between the valve stems of each pair of valves,

a guide for the cross-pieces formed on and grouped in sets and having stems in parallel relation, a cross-piece for each set of valves in operative relation to the valve stems, guide shoulders on said head to prevent rotation of the cross-pieces, a shaft arranged above the latter, bearings of the shaft fixed between the stems of each set of valves, and cams on said shaft in proximity to and laterally of each bearing and in operative rela tion to the cross-piece.

6. In a valve mechanism for internal combustion engines, the combination of cylinder head, a plurality of valves in the latter grouped in sets and having stems in parallel relation, a cross-piece for each set of valves in operative relation to the valve stems, guide shoulders on said head to prevent rotation of the cross-pieces, a shaft arranged above the latter, bearings for the shaftrfixed between the stems of each set of valves, a hanging guide rod for each crosspiece formed on each bearing, and cams on the shaft on either side of the bearings in operative relation to the cross-piece of each set of valves.

Invtestimony that'I claim the foregoing as my invention I have signed my name.

GUEO FORNACA. 

